Carbon nanotubes and nanofibres offer the potential for enhancement of a range of polymer properties. A number of types of fillers are available, ranging from single (SWNT) and multi-walled (MWNT) carbon nanotubes, with large aspect ratios (>1000) and longitudinal moduli approaching a terapascal, to more readily available vapour-grown carbon nanofibres (CNF), with longitudinal moduli of around 240GFfl.